First of all, it weighs about double that of acrylic or poly, so an old sign cabinet which is already suffering from fatigue is not gonna like having something twice as heavy to support as it was originally meant to be. Second, most people will put screws through it.... weakening it even further.
What most people do not consider is simply this........ almost all things are made to certain specifications to meet code, just like all the codes most of you complain about to do an installation. However, when placed in a situation to win a bid, MOST people here and around the world will throw code out the window and say, this should work. They are only concerned about right now and not at all... down the road. That's when the oldtimers or people who know what's happening complain about the riff-raff in the business and cutting corners. In a million years, you would never build an electric sign cabinet to spec and then fit it with 3mm ACM faces. Never. It would not meet code. Besides, there are other ways to build a box if you want a solid panel in it and it ain't the way you'd build an electric sign cabinet.
Now, some idiot here is gonna say, yeah, but if you weld a support here and one there, it will give some substantial wind resistance and make it more secure. However, that idiot doesn't enter into his/her equation that they've just added more and more weight to a can which was supposed to hold some sorta plastic face,. but doubled that weight also. Now, the thing is grossly overweight and unsafe. BUT, that same idiot will walk away after getting paid his lesser amount for doing it wrong with NO concerns what will happen after said cheap-a$$ customer's sign gives way because the whole scenario was a total disaster..... because someone didn't have the balls to explain right from wrong.
